For the manufacture of stiffened panels of composite materials such as those used in aircraft lifting surfaces co-bonding methods are known wherein stiffening elements in uncured state are joined to a skin in cured state as well as secondary co-bonding and co-curing methods.
In the co-bonding known methods of such panels curing tools in direct contact with the stiffening elements are used and, although satisfactory results are generally obtained, some problems such as the so-called “Mexican hat” concerning T-shaped stiffeners, the lack of uniformity of the co-bonding line and the presence in the foot of the stringers close to curing tools of non-working areas, cannot be avoided.
The present invention is directed to solving these problems.